Thanks for posting all your information, PabloMack. I'm sure an environment scan would provide better results as small artifacts will hardly be noticable. I think though, that things like rivers and windows will add another problem. And you get all the trees with it, which will add a lot of polys, and they won't be very nice (I think). Good for distant/overall views but not for close ups, I'd say.
Looking forward to more tests. You should take a plane and circle some interesting area....